backend developer for B2B trading

CarOnSale is an AI-powered operating system for B2B used car trading in Europe. Its platform connects software, pricing intelligence, logistics, and financing, serving more than 40,000 buyers across over 20 countries.

• Own backend development end to end, including technology selection, architecture design, and implementation of features supporting platform performance and scale;
• Build with AI-first development practices using coding agents, LLMs, and AI-assisted tools;
• Set code quality benchmarks, development practices, and CI/CD pipelines across functions and enforce them through reviews;
• Mentor engineers, share knowledge, and raise backend engineering standards;
• Challenge existing approaches and introduce better solutions when needed.

• 8+ Years of software engineering experience, including 5+ years focused on backend development;
• Deep TypeScript proficiency with strong Node.js, NestJS, and PostgreSQL experience;
• Proven experience mentoring engineers and raising engineering standards;
• Solid knowledge of Git, Docker, and CI/CD pipelines;
• Experience working with Scrum or Kanban, JIRA, and Confluence;
• English at C1 level or above, written and spoken;
• AI-native development style with practical judgment about where AI tools accelerate development;
• Based in Berlin or ready to relocate;
• Nice to have: WebSockets or other real-time systems, Elasticsearch or Lucene, automotive or B2B trading background, conversational German.

• 28 Days of annual leave;
• Company pension with a 20% employer contribution;
• Subsidised Deutschlandticket;
• FitX or Urban Sports Club membership subsidy;
• Structured onboarding with a buddy programme;
• Architecture ownership from day one;
• Access to the full European engineering team;
• Backing from a company founded in 2018 with 400 people and a €70M Series C in July 2025 led by Northzone and HV Capital.